Background: It is well known that people living with HIV (PLWH) is in higher risk for the development of depression and it has also been suggested that the use of efavirenz into the antiretroviral regimens increases even that risk. Objective: To evaluate the effect of efavirenz-containing antiretroviral regimens on the development of depression in newly ART initiated HIV patients in Ecuador. Methods: In a prospective cohort study from June 2016 to May 2017, all newly HIV diagnosed patients at the HIV/AIDS Unit of the Hospital Eugenio Espejo in Quito, Ecuador were evaluated using the Hamilton Rating Scale for Depression followed by a second assessment 8-12 weeks after antiretroviral therapy containing efavirenz was initiated. Results: A total of 79 patients, mainly males younger than 35 years were studied. Majority of them were on TDF/FTC/ EFV. Initial score in Hamilton Rating Scale revealed that less than 30% had no depression symptoms while almost 40% had mild depression. However, in the second assessment, 22.6% of the subjects had a score in the Hamilton Rating Scale compatible with severe or very severe depression (RR 1.58, 95% CI 1.09 to 2.28; p = 0.05). Conclusion: In our cohort study, depression was much higher in patients on Efavirenz-containing treatments. Therefore, assessment for depression must be essential as part of follow-up in these patients.

An oil well located offshore Southeast Asia, was completed with a dual string and after 20 years of production the drawdown decreased significantly even with gas lift mandrels located in the long string, 480m (1575ft.) above the lowest producing zone. A deep gas lift (DGL) system was installed based on field data that indicated the production could be improved by increasing the drawdown to optimize the gas lift performance. One of the main limitations was the depth of the production packer for the gas injection production. The deep gas lift system was selected as it enables the gas injection point to be moved deeper into the well, which in turn results in the ability to create a greater drawdown. The lowermost gas lift mandrel was straddled with two packers and a crossflow assembly that provided dual flow paths in a single system as well as suspending 350m (1148ft.) of 1.5in coiled tubing (CT) that acted as the injection string to a predetermined depth. The operation was the first of its kind in which the DGL system was conveyed with a CT Catenary system on board a dynamically positioned vessel (DP2); this enabled flexibility in deployment of the long bottomhole assemblies in small offshore platforms without the presence of a crane. For this operation, modifications were required in the original CT equipment to maintain well integrity, providing double barriers at every step of the installation. The DGL system was successfully and safely installed in a live well in 3 days. After its installation, the production rate increased tremendously. Similar operations will benefit from understanding the rationale in the selection of the solution, the details of the installation with the CT catenary system, the barrier systems put in place during the open-hole installation, the depth correlation methods and the lessons learned.

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For many years perforating in horizontal wells under variable conditions has been one of the biggest challenges in the South China Sea area. Being a critical step during the cycle of a well, operators have to identify the best perforating method to achieve desired results in the safest manner whilst remaining cost-effective. Perforating using coiled tubing (CT) conveyance provides a range of flexibility as an attractive method to convey long sections of guns in a single run; however, whether this technology can be considered the most appropriate solution in light of available alternatives developed in recent years, remains in question. One of the operators in Malaysia faced this situation when preparing its first perforating campaign in a field with complex extended reach wells, where the main target was to produce the maximum quantity of gas available whilst avoiding sand production. The campaign was performed with a rig present and any delay due to failure meant a huge cost impact. The operator solicited a detailed technical design and a systematic evaluation of all available options in the market to perforate the pay zones successfully. The solution implemented was based in part on the experience obtained during previous years in the Area, where different methods were used. An exhaustive statistical analysis was performed to determine the critical parameters to be the focus of the design and the selection of the most reliable technology to address the various scenarios that the campaign presented. Hydraulically actuated CT tractors, friction reducers, sterling beads, and creative use of buoyancy effect, together with using state-of-the-art CT technology were among the combinations proposed to overcome CT lockup and successfully convey the oriented guns to total depth (TD) in all wells. The intent of this paper is to provide a strong guide to CT perforating under variable conditions in horizontal wells through a thorough requirements analysis, risk evaluation and proper selection of technology. A review of the results and lessons learnt are also included. The engineering process, which has since become the benchmark in the area, can be applied with confidence as evidence by the success of the campaign.

Located in the Arabian gulf, the Qatari North Field is the largest non-associated gas field worldwide with estimated reserves exceeding 900 trillion cubic feet of recoverable gas, or approximately 10% of the world's known reserves. Development of this field present tough conditions for all aspects of well drilling and completion activities. Particular challenges for performing well intervention, which have driven operators and manufacturing and service companies to develop innovative strategies and systematic technology collaboration for intervening these fields in a safe and efficient manner. Recently, two new sub-horizontal wells with multiple reservoir zones needed to be perforated and selectively stimulated. Considering safety factors and operational efficiency, the insertion and retrieval under pressure system was identified as the best alternative to convey an average length of 600ft of 2 7/8-in. guns in single trips with coiled tubing (CT). Although this system has been successfully used in other regions, downhole adverse conditions required specifc components and implementing innovative methods, including the use of 5/16-in. braided slickline for gun deployment, and 2 3/8-in. CT with fiber optic telemetry capability for accurate depth correlation, precise actuation of the firing head system and confirmation of gun detonation. As result of a dedicated planning and preparation process, the two wells were perforated in controlled conditions and each of the applied technologies proved its value. The use of 5/16-in. braided slickline reduced the gun deployment time by at least 2 days from the planned schedule, and the H2S rated connectors and the pressure-pulse firing head gave the confidence to avoid any issues when the perforating assembly was downhole. In respect to the CT real-time telemetry system, this technology provided an exceptional indication of bottomhole conditions throughtout the operation by enabling precise control of the firing head mechanism, identification of gas/water fluid contact in the well, and monitoring of formation response, which eliminated the need for initially planned nitrogen lift operations. This paper describes the selection process of the key technologies deployed for performing CT conveyed perforating operations in two sub-horizontal wells in Qatari North Field, and discusses the workflow developed for those interventions. It then presents case studies and lessons learned and provides conclusions from the experiences gained for performing CT conveyed perforating operations in North Field.